When using checkbox, how do I cancel the last check?

checkbox3_value=get(handles.checkbox3, 'Value');
if checkbox3_value == 1
     a = [0:10]';
     b = num2str(a); c = cellstr(b);
     text(Nodelocation(:,2), Nodelocation(:,3), c);
else

end

How to not display text when else?

I tried delete and visible but it just doesn't work.